(19)

(11)

EP 0 673 499 A1

(12)

(43) Date of publication: 27.09.1995 Bulletin 1995/39 (21) Application number: 94902042.0 (22) Date of filing: 08.12.1993

(51) International Patent Classification (IPC):  G01B 7/ 30( . ) G01D 5/ 22( . ) G01D 5/ 20( . ) (86) International application number: PCT/GB1993/002510 (87) International publication number: WO 1994/014027 (23.06.1994 Gazette 1994/14)

(84) Designated Contracting States: DE FR GB IT (30) Priority: 12.12.1992 GB 19920025971 (71) Applicant: PENNY & GILES BLACKWOOD LIMITED Gwent NP2 2YD (GB)	(72) Inventor: ALEXANDER, Alfred John Kent ME2 4SA (GB) (74) Representative: Pearce, Anthony Richmond, et al  MARKS & CLERK, Alpha Tower, Suffolk Street Queensway Birmingham B1 1TT Birmingham B1 1TT (GB)